Quick Boost Guage Question...

I hear there were 2 sides to the boost guage...as in 2 springs, one for VAC one for BOOST. Well, If at idle the VAC side reads nothing, and only the boost side reads...what should I check? The guage itself, the tube from the SC? Havent really worried about it, cuz the car still drives perfect, I just cant see what VAC im pulling. It just sits a tad below ZERO at idle.

Thanks for looking,
Aaron

It sounds like the gauge. There is only one vac. line. if that was it you would have no boost showing.
good luck
joe